Problem compiling C++ in Org-mode

Problem compiling C++ in Org-mode

[Michael Hannon]

Greetings.  I'm having a problem compiling a C++ source-code block in
Org-mode.  The same C++ code compiles and runs in the shell.

The issue seems to relate to local include files.  I.e., a program that
includes only standard files, such as:

    #include <iostream>

works fine.  But Org-mode seems to be unable to find a file included from the
current directory, such as:

    #include "OtherStuff.cpp"

I've appended the Org source code and associated error message.

I've also appended the log of a successful compilation of the same source code
in the shell, as well as the details of my configuration.

What am I missing?

Thanks,

-- Mike




########## Unsuccessful attempt to compile in Org-mode

* Test

#+begin_src cpp
    
  #include <iostream>
  #include <memory>
  #include "OtherStuff.cpp"
  
  using namespace std;
  
  int main() {
  
    cout << "Hello!" << endl;
  
  }
    
#+end_src

#+results:


/tmp/babel-245846_d/C-src-24584NIQ.cpp:7:26: fatal error: OtherStuff.cpp: No
such file or directory
compilation terminated.
/bin/bash: /tmp/babel-245846_d/C-bin-24584aSW: Permission denied

########## Successful compilation in linux shell

$ cat junk.cpp
#include <iostream>
#include <memory>
#include "OtherStuff.cpp"

using namespace std;

int main() {

  cout << "Hello!" << endl;

}
$ g++ -o junk -std=c++0x junk.cpp

$ ./junk
Hello!

########## Org-mode compile uses same option as shell compile:

org-babel-C++-compiler is a variable defined in `ob-C.el'.
Its value is "g++ -std=c++0x"

Documentation:
Command used to compile a C++ source code file into an
  executable.

########## My configuration

Emacs  : GNU Emacs 23.3.1 (x86_64-redhat-linux-gnu, GTK+ Version 2.24.5)
 of 2011-06-29 on x86-01.phx2.fedoraproject.org
Package: Org-mode version 7.7 (release_7.7.328.g1a97.dirty)

Re: Problem compiling C++ in Org-mode

[Olaf Meeuwissen]

Michael Hannon <jm_hannon@yahoo.com> writes:

> Greetings.  I'm having a problem compiling a C++ source-code block in
> Org-mode.  The same C++ code compiles and runs in the shell.
>
> The issue seems to relate to local include files.  [...snip...]
> What am I missing?

> /tmp/babel-245846_d/C-src-24584NIQ.cpp:7:26: fatal error: OtherStuff.cpp: No
> such file or directory
> compilation terminated.
> /bin/bash: /tmp/babel-245846_d/C-bin-24584aSW: Permission denied

Compilation is taking place in a temporary directory, miles away from
where your org file lives.

> ########## Org-mode compile uses same option as shell compile:
>
> org-babel-C++-compiler is a variable defined in `ob-C.el'.
> Its value is "g++ -std=c++0x"

The current directory is not specified in the include path.  You would
need to add a -I option to set the (absolute path to the) directory the
org file is in.  If you have all your org files in ~/org, you could try
"g++ -std=c++0x -I~/org".

Hope this helps,
-- 
Olaf Meeuwissen, LPIC-2           FLOSS Engineer -- AVASYS CORPORATION
FSF Associate Member #1962               Help support software freedom
                 http://www.fsf.org/jf?referrer=1962

Re: Problem compiling C++ in Org-mode

[Michael Hannon]

Olaf Meeuwissen wrote:

>  Michael Hannon <jm_hannon@yahoo.com> writes:

>> Greetings.  I'm having a problem compiling a C++ source-code block in
>> Org-mode.  The same C++ code compiles and runs in the shell.
>>
>> The issue seems to relate to local include files.  [...snip...]
>> What am I missing?
>
>> /tmp/babel-245846_d/C-src-24584NIQ.cpp:7:26: fatal error: OtherStuff.cpp: No
>> such file or directory
>> compilation terminated.
>> /bin/bash: /tmp/babel-245846_d/C-bin-24584aSW: Permission denied

> Compilation is taking place in a temporary directory, miles away from
> where your org file lives.

>> ########## Org-mode compile uses same option as shell compile:
>>
>> org-babel-C++-compiler is a variable defined in `ob-C.el'.
>> Its value is "g++ -std=c++0x"

> The current directory is not specified in the include path.  You would
> need to add a -I option to set the (absolute path to the) directory the
> org file is in.  If you have all your org files in ~/org, you could try
> "g++ -std=c++0x -I~/org".

Thanks, Olaf.  That does fix the problem, and in some sense that's the obvious
solution.  On the other hand, it does seem strange to me that the end user
should have to specify the include directory.  I.e., Emacs clearly knows the
current directory ("M-x pwd", for instance), and the C++ compiler "knows" to
look in the current directory for include files enclosed in quote marks.  I
assumed that the compilation process in Org-mode would include steps similar
to:

    + remember current directory
    + write contents of source block to obscure location in /tmp
    + compile source block in obscure location,
          but remembering the starting directory for such things
          as include files

Obviously I was wrong, but it still seems a reasonable approach.

-- Mike

Re: Problem compiling C++ in Org-mode

[Olaf Meeuwissen]

Michael Hannon <jm_hannon@yahoo.com> writes:

> Olaf Meeuwissen wrote:
>
>>  Michael Hannon <jm_hannon@yahoo.com> writes:
>
>>> Greetings.  I'm having a problem compiling a C++ source-code block in
>>> Org-mode.  The same C++ code compiles and runs in the shell.
>>>
>>> The issue seems to relate to local include files.  [...snip...]
>>> What am I missing?
>>
>>> /tmp/babel-245846_d/C-src-24584NIQ.cpp:7:26: fatal error: OtherStuff.cpp: No
>>> such file or directory
>>> compilation terminated.
>>> /bin/bash: /tmp/babel-245846_d/C-bin-24584aSW: Permission denied
>
>> Compilation is taking place in a temporary directory, miles away from
>> where your org file lives.
>
>>> ########## Org-mode compile uses same option as shell compile:
>>>
>>> org-babel-C++-compiler is a variable defined in `ob-C.el'.
>>> Its value is "g++ -std=c++0x"
>
>> The current directory is not specified in the include path.  You would
>> need to add a -I option to set the (absolute path to the) directory the
>> org file is in.  If you have all your org files in ~/org, you could try
>> "g++ -std=c++0x -I~/org".
>
> Thanks, Olaf.  That does fix the problem, and in some sense that's the obvious
> solution.  On the other hand, it does seem strange to me that the end user
> should have to specify the include directory.  I.e., Emacs clearly knows the
> current directory ("M-x pwd", for instance), and the C++ compiler "knows" to
> look in the current directory for include files enclosed in quote marks.  I
> assumed that the compilation process in Org-mode would include steps similar
> to:
>
>     + remember current directory
>     + write contents of source block to obscure location in /tmp
>     + compile source block in obscure location,
>           but remembering the starting directory for such things
>           as include files

Of course, here's where Emacs would have to tell the compiler where that
starting directory would be and know what option that compiler takes to
do so.  Here's hoping that -I works everywhere ... probably not.

> Obviously I was wrong, but it still seems a reasonable approach.

Hope this helps,
-- 
Olaf Meeuwissen, LPIC-2           FLOSS Engineer -- AVASYS CORPORATION
FSF Associate Member #1962               Help support software freedom
                 http://www.fsf.org/jf?referrer=1962

Re: Problem compiling C++ in Org-mode

[Michael Hannon]

Just for the record, adding the following to my .emacs file seems to solve the problem I was having, where the C++ compiler was compiling a source block (written  to a temporary file in /tmp/...) and was unable to find an include file in the current working directory:

(setq org-babel-C++-compiler
    (concat "g++ -std=c++0x "
            "-I"
            (expand-file-name ".")
    )
)

-- Mike



>________________________________
>From: Michael Hannon <jm_hannon@yahoo.com>
>To: Olaf Meeuwissen <olaf.meeuwissen@avasys.jp>
>Cc: Org-Mode List <emacs-orgmode@gnu.org>
>Sent: Friday, November 18, 2011 12:39 AM
>Subject: Re: [O] Problem compiling C++ in Org-mode
>
>Olaf Meeuwissen wrote:
>
>>  Michael Hannon <jm_hannon@yahoo.com> writes:
>
>>> Greetings.  I'm having a problem compiling a C++ source-code block in
>>> Org-mode.  The same C++ code compiles and runs in the shell.
>>>
>>> The issue seems to relate to local include files.  [...snip...]
>>> What am I missing?
>>
>>> /tmp/babel-245846_d/C-src-24584NIQ.cpp:7:26: fatal error: OtherStuff.cpp: No
>>> such file or directory
>>> compilation terminated.
>>> /bin/bash: /tmp/babel-245846_d/C-bin-24584aSW: Permission denied
>
>> Compilation is taking place in a temporary directory, miles away from
>> where your org file lives.
>
>>> ########## Org-mode compile uses same option as shell compile:
>>>
>>> org-babel-C++-compiler is a variable defined in `ob-C.el'.
>>> Its value is "g++ -std=c++0x"
>
>> The current directory is not specified in the include path.  You would
>> need to add a -I option to set the (absolute path to the) directory the
>> org file is in.  If you have all your org files in ~/org, you could try
>> "g++ -std=c++0x -I~/org".
>
>Thanks, Olaf.  That does fix the problem, and in some sense that's the obvious
>solution.  On the other hand, it does seem strange to me that the end user
>should have to specify the include directory.  I.e., Emacs clearly knows the
>current directory ("M-x pwd", for instance), and the C++ compiler "knows" to
>look in the current directory for include files enclosed in quote marks.  I
>assumed that the compilation process in Org-mode would include steps similar
>to:
>
>    + remember current directory
>    + write contents of source block to obscure location in /tmp
>    + compile source block in obscure location,
>          but remembering the starting directory for such things
>          as include files
>
>Obviously I was wrong, but it still seems a reasonable approach.
>
>-- Mike
>
>
>
>

Re: Problem compiling C++ in Org-mode

[Eric Schulte]

A slightly cleaner solution would be the following.

(add-to-list 'org-babel-default-header-args:C
             (cons :flags (concat "-std=c++0x -I " (expand-file-name "."))))

But either the above or below configuration will likely only work if the
directory holding your .emacs is the same directory in which the
included files are held.

Best -- Eric

Michael Hannon <jm_hannon@yahoo.com> writes:

> Just for the record, adding the following to my .emacs file seems to
> solve the problem I was having, where the C++ compiler was compiling a
> source block (written  to a temporary file in /tmp/...) and was unable
> to find an include file in the current working directory:
>
> (setq org-babel-C++-compiler
>     (concat "g++ -std=c++0x "
>             "-I"
>             (expand-file-name ".")
>     )
> )
>
> -- Mike
>
>
>
>>________________________________
>>From: Michael Hannon <jm_hannon@yahoo.com>
>>To: Olaf Meeuwissen <olaf.meeuwissen@avasys.jp>
>>Cc: Org-Mode List <emacs-orgmode@gnu.org>
>>Sent: Friday, November 18, 2011 12:39 AM
>>Subject: Re: [O] Problem compiling C++ in Org-mode
>>
>>Olaf Meeuwissen wrote:
>>
>>>  Michael Hannon <jm_hannon@yahoo.com> writes:
>>
>>>> Greetings.  I'm having a problem compiling a C++ source-code block in
>>>> Org-mode.  The same C++ code compiles and runs in the shell.
>>>>
>>>> The issue seems to relate to local include files.  [...snip...]
>>>> What am I missing?
>>>
>>>> /tmp/babel-245846_d/C-src-24584NIQ.cpp:7:26: fatal error: OtherStuff.cpp: No
>>>> such file or directory
>>>> compilation terminated.
>>>> /bin/bash: /tmp/babel-245846_d/C-bin-24584aSW: Permission denied
>>
>>> Compilation is taking place in a temporary directory, miles away from
>>> where your org file lives.
>>
>>>> ########## Org-mode compile uses same option as shell compile:
>>>>
>>>> org-babel-C++-compiler is a variable defined in `ob-C.el'.
>>>> Its value is "g++ -std=c++0x"
>>
>>> The current directory is not specified in the include path.  You would
>>> need to add a -I option to set the (absolute path to the) directory the
>>> org file is in.  If you have all your org files in ~/org, you could try
>>> "g++ -std=c++0x -I~/org".
>>
>>Thanks, Olaf.  That does fix the problem, and in some sense that's the obvious
>>solution.  On the other hand, it does seem strange to me that the end user
>>should have to specify the include directory.  I.e., Emacs clearly knows the
>>current directory ("M-x pwd", for instance), and the C++ compiler "knows" to
>>look in the current directory for include files enclosed in quote marks.  I
>>assumed that the compilation process in Org-mode would include steps similar
>>to:
>>
>>    + remember current directory
>>    + write contents of source block to obscure location in /tmp
>>    + compile source block in obscure location,
>>          but remembering the starting directory for such things
>>          as include files
>>
>>Obviously I was wrong, but it still seems a reasonable approach.
>>
>>-- Mike
>>
>>
>>
>>
>

-- 
Eric Schulte
http://cs.unm.edu/~eschulte/

Re: Problem compiling C++ in Org-mode

[Sebastien Vauban]

Hi Michael,

Michael Hannon wrote:
> Just for the record, adding the following to my .emacs file seems to solve
> the problem I was having, where the C++ compiler was compiling a source
> block (written  to a temporary file in /tmp/...) and was unable to find an
> include file in the current working directory:
>
> (setq org-babel-C++-compiler
>     (concat "g++ -std=c++0x "
>             "-I"
>             (expand-file-name ".")
>     )
> )

Your previous version contained "-I~/...". I don't know why you changed it,
but this could eventually enlighten you:

    ┏━━━━[ from Cygwin's ML]
    ┃ "If a word begins with an unquoted tilde character (`~'), all of the
    ┃ characters up to the first unquoted slash (or all characters, if there
    ┃ is no unquoted slash) are considered a TILDE-PREFIX."
    ┃
    ┃ Note "word begins". I've been bitten by this in a makefile:
    ┃
    ┃ OPENSSL_DIR := ~/lib/openssl
    ┃ CPPFLAGS := -I$(OPENSSL_DIR)
    ┃
    ┃ The gcc command line then contained -I~/lib/openssl, and the ~ was not
    ┃ expanded by the shell. ${HOME}/lib/openssl would have worked.
    ┗━━━━

Best regards,
  Seb

-- 
Sebastien Vauban

Re: Problem compiling C++ in Org-mode

[Michael Hannon]

> From: Sebastien Vauban <wxhgmqzgwmuf@spammotel.com>
>> Just for the record, adding the following to my .emacs file seems to solve
>> the problem I was having, where the C++ compiler was compiling a source
>> block (written  to a temporary file in /tmp/...) and was unable to find an
>> include file in the current working directory:
>>
>> (setq org-babel-C++-compiler
>>     (concat "g++ -std=c++0x "
>>             "-I"
>>             (expand-file-name ".")
>>     )
>> )

> Your previous version contained "-I~/...". I don't know why you changed it,
> but this could eventually enlighten you:
> 
>     ┏━━━━[ from Cygwin's ML]
>     ┃ "If a word begins with an unquoted tilde character (`~'), all of the
>     ┃ characters up to the first unquoted slash (or all characters, if there
>     ┃ is no unquoted slash) are considered a TILDE-PREFIX."
>     ┃
>     ┃ Note "word begins". I've been bitten by this in a makefile:
>     ┃
>     ┃ OPENSSL_DIR := ~/lib/openssl
>     ┃ CPPFLAGS := -I$(OPENSSL_DIR)
>     ┃
>     ┃ The gcc command line then contained -I~/lib/openssl, and the ~ was not
>     ┃ expanded by the shell. ${HOME}/lib/openssl would have worked.
>     ┗━━━━
> 

Hi, Seb.  Thanks for the heads-up.  The version that I have now seems to work,
but, just FYI, the explanation for the change of syntax is explained in the
little dialogue that I had with myself:

Hmm, to get this thing to compile, I have to tack on some "-I..." stuff to my
g++ command.  This is tedious.  How can I do this automatically?

I'll bet I know: there must be some way to concatenate strings in Emacs lisp.

(Google search for some terms vaguely related to "Emacs lisp concatenate".)

(Look at one of the Google hits and stumble across an example that turns out
to use "expand-file".)

What do you suppose expand-file does?  (Try it.)  Cool!

(Break from problem-solving loop)

-- Mike